An alien has taken control of the ship, and the crew need to fight it. Spock explains the situation in terms of biology: the ship is the body, the crew are the blood cells, and the alien is the virus.

This catchy song introduces the viewer to the circulatory system and explains its basic function: to circulate blood. It also covers the four chambers of the heart.

Eddie Johnson has consumed a lot of sugar, and The Pancreas Supervisor explains how he handles the emergency situation. He covers how the pancreas reduces sugar levels in the body using insulin and describes the result of the sharp drop in sugar levels: a sugar crash.

Beakman answers quick questions about blood, veins, and their functions. They demonstrate this by having Josie dress as a "cell" and she goes to a restaurant where "blood" is the waiter that offers her food first and then takes away her waste to the kidneys and lungs. Then they have a germ come in and try to get close to the "cell" and "blood" comes in a cap and gets rid of the germ.

Beakman gives some facts about skin as an organ. Then he uses an animated clip to explain the function of skin. Using a model, he explains the different layers of skin and gives an overview of their functions. He also talks about melanin and skin color.